C 19 Only users that share a channel are allowed to send messages.
i 0.0.1 User is "invisible".
o 0.0.1 User is IRC operator.
+ q 20 User is protected, can not be kicked from a channel.
r 0.0.1 User is restricted.
R (1) 19 User is registered (e.g. by NickServ).
s 0.4.0 User wants to receive server notices.
k 0.6.0 Channel has a "key" (a password).
l 0.6.0 Channel has a user limit.
m 0.3.0 Channel is moderated, only "voiced" users can send messages.
+ M 20 Only registered users (and IRC Ops) can send messages.
n 0.3.0 Channel doesn't allow messages of users not being members.
O 18 Only IRC operators are allowed to join this channel.
P 0.5.0 Channel is "persistent".
+ Q 20 Nobody can be kicked from the channel.
r (1) 19 Channel is "registered" (e.g. by ChanServ).
R 19 Only registered users are allowed to join this channel.
s 0.9.0 Channel is "secret".
mode since description
+ q 20 User is channel owner can only be set by a service, other
+ owner and irc op. Can promote other users to q, a, o, h, v.
+ a 20 User is channel admin and can promote other users to v, h, o
o 0.2.0 User is channel operator and can op/kick/... other members.
+ h 20 User is half op and can set channel modes imntvIbek and kick
+ voiced and normal users.
v 0.2.0 User is "voiced" and can speak even if channel is moderated.